This application pertains to the art of workpiece handling and particularly to vibratory feeders for handling and conveying workpieces between successive work or escapement stations.
The invention is particularly applicable to interconnectable modular work stations where each module is particularly adapted to facilitate a specific manufacturing operation or function such as assembly, polishing, drilling, and the like. The work station modules may be connected in a generally linear array such that the workpieces are moved from module to module as each operation or function is performed. It will be appreciated, however, that those skilled in the art may readily adapt the invention to other manufacturing operations as well as to alternative handling and processing arrangements or environments.
Heretofore, various manufacturing assemblies have been devised in which workpieces are placed on a pallet or other carrier and moved automatically from one work station to another. In one such assembly, a series of pallets were adapted for selective engagement with and disengagement from a continuously moving chain. When a pallet reached a work station, it automatically disengaged the chain in anticipation of the operation being performed. Once the operation had been completed, the pallet reengaged the chain and was moved to the next work station. In this system, the pallets tended to be suddenly accelerated and deaccelerated resulting in frequent impacts with each other. Moreover, the equipment utilized was complicated and expensive and was best used for large workpieces such as engine blocks, transmission assemblies, and the like.
Others in the field have suggested disposing independent belt drives between work stations for moving pallets containing workpieces between subsequent work stations. The belt drives may be interrupted between work stations to allow the pallet and attached workpieces to be tipped, rotated, or otherwise have its orientation adjusted to facilitate the next operation. The belts maintained the pallets at fixed intervals which could not be contracted or eliminated. Further, the belts were constrained to moving all pallets along the belt simultaneously and, thus, could not move to receive a pallet at one end without moving to discharge or advance a pallet at the other end. Such systems, again, were complicated, expensive and not well suited to the assembly of moderate or small components.
Vibratory feeders have been used for many years to convey workpieces from one location to another. The jostling movement caused by vibratory feeders is unsuitable for some subassemblies, workpieces, or partially assembled workpieces. For example, if a shallow race containing a plurality of ball bearings were to be transported, the ball bearings would tend to bounce out of the race. A similar problem would tend to arise in the other prior art systems in which the pallets were accelerated or deaccelerated suddenly. It is further known in vibratory feeders to line the feeder with polypropylene fiber material to reduce noise and protect delicate parts.